In this paper, a new methodology for deriving the velocity and the acceleration information of a digital encoder through processing its pulse train, is presented. The proposed method is based on accurate time measurement (with picosecond accuracy) as well as encoder pulse counting in adaptively changing time intervals, providing thus a wide-range velocity evaluation with very good accuracy. The method offers better response times at low speeds and very high-accuracy at the full range of measured velocities. By using the proposed method, the velocity measurement accuracy is improved compared to currently known methods, since high-resolution time-to-digital converters (TDC) are included in the design. The increased accuracy in velocity measurement allows the application of the simple arithmetic differentiation method on the velocity information in order to derive the acceleration, which in other cases would not be suggested due to accumulated quantization noise. A digital signal processor (DSP) also allows the implementation of numerous other methods to calculate acceleration. The proposed configuration has been implemented in specific hardware (FPGA), reserving thus the computational power of the system controlling DSP for high-level control tasks.

An intelligent system for diagnosis of capsule endoscopic imagesKodogiannis, V., Boulougoura, M. and Wadge, E. 2005. An intelligent system for diagnosis of capsule endoscopic images. in: Proceedings of the Second International Conference on Computational Intelligence in Medicine and Healthcare (CIMED 2005). 29th June - 1st July 2005, Lisbon, Portugal London, UK IEEE . pp. 340-347

In vitro determination of skin bilirubin using chromatic modulationTomtsis, D., Kodogiannis, V. and Zissopoulos, D. 2001. In vitro determination of skin bilirubin using chromatic modulation. in: Building new bridges at the frontiers of engineering and medicine: 2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society. 25-28 October 2001, Istanbul, Turkey USA IEEE .